Hi, just came home with my new (to me) 1986 4+3 l98 c4 corvette with 90k miles on the clock. I just want to thank the guys on this forum for helping me buy the right one and helping me see some imperfections that I would need to fix on the car. This will be my dd that will sooner rather than later be a dd/track toy.

The thing is that it has some quirks and I don't know if they are normal or not. some of them are:
1. coolant temp gets up past 220* but hasn't gone past 227*yet. Is this normal? should it be lower?

2. the top up windows up the car shakes a bit. not terribly but just enough to make it kinda nervous past upper speed limits. I know its and old car with 90k on the odo so i think kit might be suspension bushings and wheel bearings. is this possible, likely, normal?

3. there are no map lights on the car. at least none that work. do these things have built in map lights that are supposed to illuminate?

4. the climate controls don't seem to work. it is an automatic climate control system so it has a readout (that doesn't work) and none of the buttons on it seem to do anything. do these fail often as a unit or are they pretty reliable? if they are reliable where can I find the fuse to the system to see if its getting power? would that fuse also power the radio because that doesn't turn on either.

5. the window seals seep water in to the cabin. how can I fix that without replacing the seals?

6. The service engine light is also on but intermittent. (it will be on one time I start the car but not the next time, then shut down restart its on again.) is that a "check engine" light or is it more of oil change soon light? need to know for smog.

 

I have an 87 so should be about the same except for the internals of the engine.

No#1. I'm pretty sure that's normal. These engines ran a little hot. If you have an auxiliary fan in front of the radiator, that doesn't come on till about 235 degrees. I wired mine so I can turn the Aux fan on any time I want.

No#3. There's a rocker switch on the bottom of the rear view mirror which turn on/off the map light which is also on the bottom of the mirror.

No#4 All the fuses are located at the end of the dashboard on the passenger side. You have to open the passenger door to see the cover of the fuses. There's a **** in the corner of the cover that turns to let the cover come off but sometimes you need a finger nail or small screwdriver to pull the cover off after turning the ****. The fuses are marked as to what they do or it's printed in the owners manual.

No#5 What does the seal on the top look like. If it's worn it won't seal properly and it will let water drip into the inside of the car.

No#6 You have an OBD1 access port under the dash about where your right knee is. The Service Engine light is telling you that there's a fault that one of the sensors sees and that it's stored in the computer. You can use an OBD1 scanner in the access port or there's a trick that lets you pull the fault codes yourself. There's about 10 holes in the access port. The top two on the right hand side can be used to get the fault codes. With a small wire or paper clip. Insert the ends into the top two holes and watch the service engine light It will blink once then pause then blink twice. This is code 12 which indicates the computer is in diagnostic mode. Next it will flash any stored codes. Three times for 3, four times for 4 etc. The codes are stored in pairs. Write down the numbers that it flashes. The code will only show you the number 12 (3 times) if there's no codes stored. Come back to the forum and let us know what numbers the computer flashes.

 

https://www.corvetteforum.com/techti...D=92&TopicID=2
https://www.corvetteforum.com/techti...=118&TopicID=2
Take some time to explore the Tech Tips in the C4 Tech/Performance section here. Enjoy!

 

@corvetteronw
Thank you. I didn't see these before. These are bound to be very helpful.

 

1, Normal. Fan doesn't come on to cool the engine until ~227-230*F.

2. Jack the car, check suspension, wheel bearings, tire balance, drive shaft u-joints. You didn't mention the frequency of the vibration.

 

what is normal?
been asking that question myself for a few years now..

You hit on 6 of the most commonly asked questions posted here.
So heres a few for you;
1. What are your mechanical abilities?
2. Are you prepared to get dirty?
3. Are you prepared to spend some money?
4. Will you purchase a Factory Shop Manual (FSM) to use as a reference? (Chilton manuals don't count.)

There are a lot of very knowledgeable people here that can walk you through the process of repairs.
Good Luck

As for one of your questions;
5. the window seals seep water in to the cabin. how can I fix that without replacing the seals?

The rubber parts on your car are how old? 28 years!
With the exception of using duct tape, the only answer is to replace the seals.
Your looking at a couple hundred dollars to replace the door/window seals alone.

Check out Willcox, Corvette Central, Eklers, Mid America for starters.

 

The map lights are in the doors. Look closely and you will see a molded in "PRESS". Push there and the light will come on. Push again to turn it off.

The climate control uses two fuses. The CTSY/CLK fuse supplies power all the time to remember the settings. The GAUGES fuse supplies power when the ignition is turned on.

The radio also uses two fuses. The CTSY/CLK fuse supplies power all the time to remember the settings. There is also a RADIO fuse.

Change oil lights came much later. The SES (Service Engine Soon) light is the same as a CEL (Check Engine Light). You should pull the error codes out of the ECM:

http://forums.corvetteforum.com/1574918379-post18.html
http://corvettephotographs.com/c4vettes/codes.htm

What they mean:

http://forums.corvetteforum.com/1576116036-post35.html
http://home.earthlink.net/~cliff_har...onditions.html

 

Thanks for the help. So I did the check engine light diagnostic procedure and it said code 14. I do know that the PO did replace the radiator and thermostat on the vehicle. Could this be a logged code that just needs deleting. I haven't seen it get past 226* F.

 

Code#14: Coolant sensor on low voltage side.

The Coolant Temperature Sensor in buried deep under the throttle body on our cars. Yes, I'd delete the fault code and see if it comes back before changing the sensor.

 

nope. it came back. will diagnose further.